To my knowledge there isn't a single shortcut that hides both the icons and toolbar but try this: Right click on the desktop, in the menu select View > Show desktop icons. If this works toolbar could be hidden as well.
If not then most likely your explorer.exe process didn't load correctly or crashed. try rebooting first. If issue persists you can click Ctrl+Alt+Delete and start task manager. Under Processes fined Explorer.exe and click end task. Then click back to Applications tab, click New Task... type in explorer.exe and click ok.